Anti‐Neoplastic Effects of Coffee on Gastrointestinal Cancer as Influenced by the Dietary Background: A Cross‐Sectional Study Based on NHANES 2001–2018

BACKGROUND: Coffee consumption has been strongly associated with gastrointestinal cancers, but the relationship is controversial. This study seeks to assess their correlation under different dietary backgrounds considering the substantial impact of the food matrix on the effects of bioactive compounds in coffee. METHODS: We selected 29,422 adults from 2001 to 2018 National Health and Nutrition Examination Survey (NHANES), categorizing their dietary backgrounds based on food groups and dietary patterns for the study. RESULTS: The results showed that the incidence of gastrointestinal cancers was 6.25‰, and the incidence was higher in participants consuming coffee (p < 0.001). The adjusted ORs (95% CI) for gastrointestinal cancers risk by coffee consumption with specific dietary habits were 0.820 (0.814-0.826) for a low-salt diet, 0.703 (0.695-0.710) for drinking tea, and 0.581 (0.576-0.586) for high vegetable intake. Factor analyses identified three dietary patterns, and participants who scored higher in the "Western Pattern" and "Balanced Pattern" had a reduced risk of gastrointestinal cancers after consuming coffee, with ORs (95% CIs) of 0.753 (0.746-0.760) and 0.963 (0.954-0.972), respectively. In contrast, coffee consumption linked to higher gastrointestinal cancer risk in participants scoring high on "Vegetarian pattern" with an OR (95% CI) of 1.707 (1.692-1.721). CONCLUSIONS: The anti-neoplastic effects of coffee on gastrointestinal cancer are related to dietary background. Based on the findings of this study, we recommend that individuals with dietary patterns classified as "Western" or "Balanced" consume coffee, as it may help reduce the risk of gastrointestinal cancer. Conversely, vegetarians may not experience the same benefits from coffee consumption.